Heat recovery device for boiler air heater

Abstract

This utility model relates to the field of waste heat recovery technology, specifically a heat recovery device for a boiler air heater. It includes a heat source pipeline, a cold source pipeline, and a hot water tank. The heat source pipeline comprises a reducing connector section and at least two large-diameter tee sections spaced apart on either side. The left, right, and rear ends of the large-diameter tee sections are fixedly installed to the large-diameter ends of the reducing connector sections. Each pair of adjacent large-diameter tee sections is fixedly installed together via the small-diameter ends of the reducing connector sections. This utility model features a reasonable and compact structure, is easy to use, and by incorporating large-diameter tee sections, its expanded diameter structure effectively reduces flue gas velocity and extends residence time. Furthermore, by using a spiral heat exchange pipeline, its thin tube structure allows for faster heat absorption, improving heat exchange efficiency. It is characterized by stability, high efficiency, and excellent heat exchange performance.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery and treatment technology, and is a heat recovery device for boiler heaters. Background Technology

[0002] As a core auxiliary unit of the boiler thermal system, the boiler air heater's core function is to heat the incoming cold air to a suitable temperature by exchanging heat with air through a heat source (such as waste heat from flue gas, steam extraction from turbines, or waste heat from condensate drains), thereby improving combustion efficiency and reducing exhaust gas temperature. However, in existing technologies, after the air heater completes the heat exchange, the low-temperature flue gas from the heat source side is usually directly discharged into the atmosphere without a deep waste heat recovery device. This discharge method results in the residual low-temperature sensible heat in the heat source (such as sensible heat carried by the flue gas even when the temperature drops below 90°C) not being utilized, causing energy waste and directly weakening the overall improvement in boiler thermal efficiency. Summary of the Invention

[0003] This utility model provides a heat recovery device for boiler air heaters, which overcomes the shortcomings of the prior art. It can effectively solve the problem that after the existing boiler air heaters are used, the low-temperature flue gas on the heat source side is directly discharged into the atmosphere without any residual heat recovery.

[0004] The technical solution of this utility model is achieved through the following measures: A heat recovery device for a boiler air heater includes a heat source pipeline, a cold source pipeline, and a hot water tank. The heat source pipeline includes a reducing connector section and at least two large-diameter tee sections spaced apart on the left and right sides. The left, right, and rear ends of the large-diameter tee sections are fixedly installed together with the large-diameter ends of the reducing connector sections. Every two adjacent large-diameter tee sections are fixedly installed together through the small-diameter ends of the reducing connector sections. A hot water tank is provided on the lower right side of each large-diameter tee section. Each section is equipped with a cold source pipeline, which includes an inlet water pipeline, a heat exchange pipeline, and an outlet water pipeline. The rear end of the reducer connection section has a sealing plug on its inner side. The sealing plug has a through-hole in the center. The rear part of the inlet water pipeline is installed in the installation hole. The front end of the inlet water pipeline is fixedly connected to the left end of the heat exchange pipeline. The right end of the heat exchange pipeline is fixedly connected to the left end of the outlet water pipeline. The right side of the reducer connection section has an installation outlet on its lower right side. The right end of the outlet water pipeline is fixedly connected to the inlet of the hot water tank through the installation outlet.

[0005] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution: The heat exchange pipelines mentioned above can be spiral pipelines.

[0006] The above may also include a first pressure relief valve, a first solenoid valve, and a first drain line. The hot water tank is equipped with a first pressure relief valve, and the outlet of the hot water tank is fixedly connected to a first drain line. The first drain line is equipped with a first solenoid valve.

[0007] The above may also include guide needles, condensate tanks and condensate discharge pipelines. Several guide needles are provided at intervals on the left and right sides below the heat exchange pipeline. A condensate outlet is provided on the lower side of the large-diameter tee pipe section corresponding to the position below the heat exchange pipeline. A condensate tank is provided in the lower middle part of each large-diameter tee pipe section. A condensate discharge pipeline is fixedly connected between the water inlet end of the condensate tank and the condensate outlet.

[0008] The above may also include a second pressure relief valve, a second solenoid valve, a third solenoid valve, and a second drain line. The condensate tank is equipped with a second pressure relief valve, the outlet of the condensate tank is fixedly connected to a second drain line, the second drain line is equipped with a second solenoid valve, and the condensate discharge line is equipped with a third solenoid valve.

[0009] The above may also include a filter drawer and filter media. The upper front side of the condensate tank is provided with a square hole for installation. The filter drawer is provided inside the square hole for installation. The filter media is provided inside the filter drawer. The lower side of the filter drawer is provided with a drain hole.

[0010] The aforementioned filter media can be bamboo or wood charcoal filter screens.

[0011] This utility model has a reasonable and compact structure and is easy to use. By setting a large-diameter tee pipe section, its enlarged diameter structure effectively reduces the flue gas velocity and extends the residence time. By setting a spiral heat exchange pipeline, its thin tube structure can absorb heat more quickly and improve the efficiency of heat exchange. It has the characteristics of stability, high efficiency and good heat exchange effect. Attached Figure Description

[0012] Appendix Figure 1 This is a top sectional view of embodiments 1 to 7 of this utility model.

[0013] Appendix Figure 2 For the appendix Figure 1 A schematic diagram of the three-dimensional structure.

[0014] Appendix Figure 3 For the appendix Figure 1 A three-dimensional structural diagram of the intermediate cooling source pipeline and hot water tank.

[0015] Appendix Figure 4 For the appendix Figure 1 Enlarged right-side cross-sectional view of the condensate tank.

[0016] The codes in the attached diagram are as follows: 1 is the reducer connection pipe section, 2 is the large-diameter tee pipe section, 3 is the hot water tank, 4 is the inlet water pipe, 5 is the heat exchange pipe, 6 is the outlet water pipe, 7 is the sealing plug, 8 is the first pressure relief valve, 9 is the first drain pipe, 10 is the guide needle, 11 is the condensate tank, 12 is the condensate discharge pipe, 13 is the second pressure relief valve, 14 is the second drain pipe, 15 is the filter drawer, and 16 is the filter packing. Detailed Implementation

[0017] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.

[0018] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0019] The present invention will be further described below with reference to the embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 , 2As shown in Figures 3 and 4, the heat recovery device for the boiler's air heater includes a heat source pipeline, a cold source pipeline, and a hot water tank 3. The heat source pipeline includes a reducing connector section 1 and at least two large-diameter tee sections 2 spaced apart on the left and right sides. The left, right, and rear ends of the large-diameter tee sections 2 are fixedly installed together with the large-diameter ends of the reducing connector section 1, respectively. Every two adjacent large-diameter tee sections 2 are fixedly installed together through the small-diameter ends of the reducing connector section 1. A hot water tank 3 is located on the lower right side of each large-diameter tee section 2, and a cold source pipeline is installed inside each large-diameter tee section 2. The cold source pipeline includes an inlet water pipeline 4, a heat exchange pipeline 5, and an outlet water pipeline 6. A sealing plug 7 is provided on the inner side of the rear end of the reducer connecting pipe section 1 located at the rear. The sealing plug 7 has a through installation hole in the center. The rear part of the inlet water pipeline 4 is installed in the installation hole. The front end of the inlet water pipeline 4 is fixedly connected to the left end of the heat exchange pipeline 5. The right end of the heat exchange pipeline 5 is fixedly connected to the left end of the outlet water pipeline 6. An installation outlet hole is provided on the lower right side of the reducer connecting pipe section 1 located on the right. The right end of the outlet water pipeline 6 is fixedly connected to the inlet end of the hot water tank 3 through the installation outlet hole. During use, the low-temperature flue gas from the heat source side of the boiler air heater is connected to the heat source pipeline, and the water to be heated is connected to the cold source pipeline. After the water to be heated and the low-temperature flue gas have fully exchanged heat, they flow into the hot water tank 3. The heat source side achieves the gradient conversion of fluid kinetic energy to thermal energy through the large-diameter tee pipe section 2. Its expanded diameter structure effectively reduces the flue gas velocity and prolongs the residence time, causing the heat to form a slow-release transfer field in the large-diameter tee pipe section 2. This allows the cold source side in the heat exchange pipeline 5 to absorb heat more quickly, improving the efficiency of heat exchange. The cold source side after heat exchange enters the hot water tank 3, making full use of the low-temperature flue gas waste heat from the heat source side. This effectively solves the problem that after the existing boiler air heater is used, the low-temperature flue gas from the heat source side is directly discharged into the atmosphere without any waste heat recovery.

[0020] The heat recovery device for the boiler air heater can be further optimized and / or improved according to actual needs: Example 2: As shown in the attached document Figure 1 , 2 As shown in Figures 3 and 4, the heat exchange pipeline 5 is a spiral pipeline. During operation, the spiral heat exchange pipeline 5 and the large-diameter tee section 2 work together to construct a composite heat recovery system. On the heat source side, the large-diameter tee section 2 achieves a gradient conversion of fluid kinetic energy into thermal energy. Its expanded diameter structure effectively reduces the flue gas velocity and prolongs the residence time, promoting the formation of a slow-release heat transfer field within the large-diameter tee section 2. On the cold source side, the spiral heat exchange pipeline 5, with its multi-stage curved flow channel characteristics, generates strong turbulent pulsations in the narrow pipe diameter. Through the combined action of centrifugal force and shear force, the boundary layer disturbance is enhanced, allowing the cold source side to absorb heat more quickly due to the narrower heat exchange pipeline 5, thus improving the efficiency of heat exchange.

[0021] Example 3: As shown in the attached document Figure 1 , 2As shown in Figures 3 and 4, the system also includes a first pressure relief valve 8, a first solenoid valve, and a first drain line 9. The first pressure relief valve 8 is installed on the hot water tank 3, and the outlet of the hot water tank 3 is fixedly connected to the first drain line 9, which is equipped with the first solenoid valve. Installing the first solenoid valve on the drain line of the hot water tank 3 enables intelligent timing control of hot water discharge. By monitoring boiler load fluctuations and changes in heat user demand in real time, the hot water delivery rhythm is dynamically adjusted to avoid thermal inertia lag effects caused by sudden temperature changes. Furthermore, the rapid response characteristics of the solenoid valve can synchronously coordinate the start-stop logic of the heat recovery system and downstream heat-using equipment. When the heater switches operating modes or suddenly shuts down, the pressure gradient of the hot water circulation system is maintained through programmed logic to prevent flash vaporization caused by sudden changes in flow rate of high-temperature hot water. The first pressure relief valve 8 establishes a pressure buffer mechanism, which can release pressure... The transient pressure fluctuations caused by temperature stratification or external impacts in the hot water tank 3 are eliminated by removing the energy oscillations of steam condensation and revaporization within the sealed container, thus preventing leakage of the sealing surface or fatigue damage to the welds due to pressure instability. Therefore, a triple-coupled control system of pressure-flow-temperature is formed by the coordinated action of the first pressure relief valve 8 and the first solenoid valve. This system ensures the stable delivery of waste heat from hot water to the plant heating or process heat supply, reduces thermal expansion stress in the pipeline through pressure buffering, extends the service life of the equipment, and provides a stable temperature field environment for subsequent heat exchange processes, reducing the decrease in heat exchange efficiency caused by pressure fluctuations.

[0022] Example 4: As shown in the appendix Figure 1 , 2 As shown in Figures 3 and 4, the system also includes guide needles 10, a condensate tank 11, and a condensate discharge pipeline 12. Several guide needles 10 are spaced apart on the lower left and right sides of the heat exchange pipeline 5. A condensate outlet is located on the lower side of a large-diameter tee section 2 corresponding to the position below the heat exchange pipeline 5. A condensate tank 11 is located in the lower middle of each large-diameter tee section 2. The inlet end of the condensate tank 11 is fixedly connected to the condensate outlet via the condensate discharge pipeline 12. During use, the guide needles 10 facilitate condensate collection; the condensate tank 11 and condensate discharge pipeline 12 recover condensate. As a byproduct of phase change heat recovery, the condensate's temperature is highly matched to the boiler feedwater requirements and can be directly reused in the boiler feedwater system, reducing chemical reagent consumption and regeneration wastewater discharge in the softened water preparation process, while also avoiding steam drum thermal stress fluctuations caused by excessively low feedwater temperature.

[0023] Example 5: As shown in the attached document Figure 1 , 2As shown in Figures 3 and 4, the system also includes a second pressure relief valve 13, a second solenoid valve, a third solenoid valve, and a second drain line 14. The condensate tank 11 is equipped with the second pressure relief valve 13, and the outlet of the condensate tank 11 is fixedly connected to the second drain line 14. The second drain line 14 is equipped with the second solenoid valve, and the condensate discharge line 12 is equipped with the third solenoid valve. During use, by setting the second and third solenoid valves, precise dynamic control of condensate discharge can be achieved, automatically adjusting the drainage rhythm according to the real-time operating status of the system, avoiding overflow waste caused by water level fluctuations or the risk of air backflow caused by excessively low liquid levels. Furthermore, by setting the second pressure relief valve 13, the system can effectively release transient pressure peaks in the condensate tank 11 caused by temperature differences or water hammer effects, eliminating the safety hazard of abnormal pressure accumulation within the sealed container and preventing seal failure due to overpressure deformation of the tank body.

[0024] Example 6: As shown in the appendix Figure 1 , 2 As shown in Figures 3 and 4, the system also includes a filter drawer 15 and filter media 16. A square mounting hole is provided on the upper front side of the condensate tank 11, within which the filter drawer 15 is installed. The filter media 16 is installed inside the filter drawer 15, and a drain hole is provided on the lower side of the filter drawer 15. During use, the condensate is treated by the filter media 16, which significantly improves water purification efficiency and enhances system operational stability. Furthermore, the filter drawer 15 facilitates the replacement of the filter media 16.

[0025] Example 7: As attached Figure 1 , 2 As shown in Figures 3 and 4, filter media 16 is a bamboo charcoal filter screen. During use, the porous fiber structure of bamboo charcoal material can efficiently trap suspended particles, colloidal substances, and microbial pollutants in condensate. Its surface rich in natural mineral layers can catalytically decompose harmful components such as phenols and aldehydes in organic matter, while removing residual acidic gaseous substances through microporous adsorption. Compared to traditional filter media, the natural weak alkalinity of bamboo charcoal can neutralize low-concentration acidic substances in condensate, effectively inhibiting uniform corrosion and localized pitting corrosion of metal pipes, and extending the service life of the boiler body and auxiliary equipment. Furthermore, the biofilm formed on the surface of bamboo charcoal can selectively adsorb heavy metal ions, reducing water hardness and scaling tendency, creating a better operating environment for subsequent water treatment systems. Its renewable nature also meets the requirements of industrial circular economy, reducing resource consumption and the risk of secondary pollution.

[0026] The above technical features constitute the preferred embodiment of this utility model, which has strong adaptability and the best implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A heat recovery device for a boiler air heater, characterized by The system includes heat source pipelines, cold source pipelines, and a hot water tank. The heat source pipelines consist of reducing connector sections and at least two large-diameter tee sections spaced apart on either side. The left, right, and rear ends of each large-diameter tee section are fixedly installed to the large-diameter ends of the reducing connector sections. Every two adjacent large-diameter tee sections are fixedly installed together via the small-diameter ends of the reducing connector sections. A hot water tank is located on the lower right side of each large-diameter tee section. Each large-diameter tee section contains a cold source pipeline, which includes an inlet water supply line. The pipeline, heat exchange pipeline, and outlet pipeline have a sealing plug on the inner side of the rear end of the reducer connection section. The sealing plug has a through installation hole in the center. The rear part of the inlet pipeline is installed in the installation hole. The front end of the inlet pipeline is fixedly connected to the left end of the heat exchange pipeline. The right end of the heat exchange pipeline is fixedly connected to the left end of the outlet pipeline. The right side of the reducer connection section is provided with an installation outlet hole. The right end of the outlet pipeline is fixedly connected to the inlet end of the hot water tank through the installation outlet hole.

2. The heat recovery device for a boiler air heater according to claim 1, characterized by The heat exchange pipeline is a spiral pipeline.

3. The heat recovery device for a boiler heater according to claim 1 or 2, characterized in that It also includes a first pressure relief valve, a first solenoid valve, and a first drain line. The hot water tank is equipped with a first pressure relief valve, and the outlet of the hot water tank is fixedly connected to a first drain line. The first drain line is equipped with a first solenoid valve.

4. The heat recovery device for a boiler heater according to claim 1 or 2, characterized in that It also includes guide needles, condensate tanks and condensate discharge pipelines. Several guide needles are provided at intervals on the left and right sides below the heat exchange pipeline. A condensate outlet is provided on the lower side of the large-diameter tee pipe section corresponding to the position below the heat exchange pipeline. A condensate tank is provided in the lower middle part of each large-diameter tee pipe section. A condensate discharge pipeline is fixedly connected between the water inlet end of the condensate tank and the condensate outlet.

5. The heat recovery device for a boiler air heater according to claim 3, characterized in that It also includes guide needles, condensate tanks and condensate discharge pipelines. Several guide needles are provided at intervals on the left and right sides below the heat exchange pipeline. A condensate outlet is provided on the lower side of the large-diameter tee pipe section corresponding to the position below the heat exchange pipeline. A condensate tank is provided in the lower middle part of each large-diameter tee pipe section. A condensate discharge pipeline is fixedly connected between the water inlet end on the upper side of the condensate tank and the condensate outlet.

6. The heat recovery device for a boiler air heater according to claim 4, characterized in that... It also includes a second pressure relief valve, a second solenoid valve, a third solenoid valve, and a second drain line. The condensate tank is equipped with a second pressure relief valve, and the outlet of the condensate tank is fixedly connected to a second drain line. The second drain line is equipped with a second solenoid valve, and the condensate discharge line is equipped with a third solenoid valve.

7. The heat recovery device for a boiler air heater according to claim 5, characterized by It also includes a second pressure relief valve, a second solenoid valve, a third solenoid valve, and a second drain line. The condensate tank is equipped with a second pressure relief valve, and the outlet of the condensate tank is fixedly connected to a second drain line. The second drain line is equipped with a second solenoid valve, and the condensate discharge line is equipped with a third solenoid valve.

8. The heat recovery device for a boiler air heater according to claim 4, characterized by It also includes a filter drawer and filter media. The upper front of the condensate tank has a square hole for installation, a filter drawer is installed inside the square hole, a filter media is installed inside the filter drawer, and a drain hole is provided on the lower side of the filter drawer.

9. The heat recovery device for a boiler heater according to claim 5 or 6 or 7, characterized in that It also includes a filter drawer and filter media. The upper front of the condensate tank has a square hole for installation, a filter drawer is installed inside the square hole, a filter media is installed inside the filter drawer, and a drain hole is provided on the lower side of the filter drawer.

10. The heat recovery device for a boiler air heater according to claim 9, characterized by The filter media is a bamboo charcoal filter screen.

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